Stay-bolt for boilers.



J. BOERO.

STAY BOLT FOR BOILERS. APPLIOATION nmm MAR. 22, 1912.

1,050,097. Patented Jan. 14, 1913 IN VENT 0R:

4 I I BY '6 @W! JOSEPH BOERO, OF NEW YORK, N. Y.

STAY-BOLT FOR BOILERS.

Specification of Letters Patent.

Application filed March 22, 1912.

To all 2.0/1 0m- 6 may concern Be it known that I, JOSEPH BUERO, a cit-izen of the United States, residing in the borough of Manhattan, city, county, and State of New York, have invented a new and useful Improvement in Stay-Bolts for Boilers,

of which the following is a description.

This invention relates to boilers and furnaces, and particularly to stay-bolts for securing together the fire-box plate and the outer shell of the boiler.

Among the objects of my invention may be noted the following: to provide a'staybelt which cannot be corroded and thereby destroyed during the use of the'boiler; to provide a stay-bolt which, when fractured will act as a tell-tale and will not empty the contents of the boiler into the furnace; and to provide means by which the bolt may be securely fastened or connected to the firebox plate without riveting, etc.

In order that my invention may be clearlyunderstood, I have provided drawings wherein Figure 1 is a sectional elevation showing the manner in which my'stay-bolt is applied in use; Fig. 2 is an elevation of the inside of Fig. 1; Fig. 3 is a longitudinal central section of my stay-bolt; Fig. 4 is a section on the line 4-4 of Fig. 3; Fig. 5 is a view similar to Fig. 1, showing the operation of the device in case the bolt fractured; Fig. 6 is an elevation of the plug or wedge; and Fig. 7 is a view similar to Fig. 6 showing another form of plug.

Primarily, it should be understood that the usual practice in connection with bolting together the fire-box,and outer shell of the boiler is to employ a double headed bolt or a bolt which, after it is-screwed or driven in, has its end overturned so as to produce a head or rivet on the inner side of the the box plate. This is objectionable for many reasons, among which may be mentioned that, after a certain length of time, the metal of the bolt exposed to the fire becomes eaten away by the corrosive action of the products of combustion which produce acids exceedingly injurious to metals of which the bolts are usually made. The bolt-head and its body are thereby gradually eaten away, making the bolt loose and the fire-box leak. Furthermore, in case of accident, resulting in fracture of the body of the bolt within the boiler, water in the latter, in case the Patented Jan.14=,1913.

Serial No. 685,407.

bolt used be hollow, \1 il be admitted to the fire-box which, of course, is objectionable for obvious reasons.

With my invention the foregoing objections are completely overcome and numerous advantages are obtained; and in order that the details of myinvention may be clearly understood, reference is bad to the accompanying drawings wherein z.

The numeral 1. indicates theback of the fire-box, 2 the outer shell of the boiler, 3

the water sp, ce, 4 the bodyof the bolt passing, through thewater space, which boltbody may be threaded throughout its length or only at its inner end 5 and outer end 6 as shown in the several drawings, the lat.- ter being the preferred form. The body of the bolt is bored centrally from end to end as at 7. and at its outer end is provided with a head 8, the inner surface of which bears tightly against the outer surface of the outer shell 2. The body of the bolt is usually made of wrought iron and when properly inserted assumes the relative position shown in Figs. 1. and Instead of employing a head or rivet at the inner end oi the belt, I eliminate the head completely, thus avoiding the accumulation of products of combustion about the inner end of the bolt and consequently eliminating the possibility of corrosive action of said products of combustion. This also gives a smooth surface to the firebox which is desirable.

In order to firmly set the inner end of the bolt in the plate of the fire-box, I employ a plug indicated by 9 which may be either solid, as shown in Fig. 6, or centrally bored as indicated at 10 by the dotted lines in Fig. 7. This plug is made of a ,much harder metal such, for example, as steel and is in the form of a wedge with an inner reduced and rounded end 11. The plug is' driven into the bore at the inner end of the bolt with considerable force, resulting in spreading the metal of the end of the bolt and in binding and, so to speak, forging together the screw threads of the inner end of the bolt and the metal of the plate of the fire-box. This condition is illustrated in Fig. 3. To remove the plug, in the event it is desired to remove the bolt for any reason, a metal rod is driven through the bore from the outer end of the bolt until it engages the inner end of the plug, whereupon a heavy blow will drive the plug from its seat, thus making it pos sible to remove the bolt in the ordinary manner.

By plugging the inner end of the bolt, as described, 1f the body of the bolt becomes fractured sufliciently to permit the water in the jacket to enter the bore of the bolt, the said bore will immediately act as a tell-tale since the waterzwill be projected through the outer end of the bolt. The presence of the plug in the inner end of the bolt revents the water being injected into the re-box, this being an important feature of my invention. The plug, however, may be bored, as shown in Fig. 7; but, since said bore is considerably less in diameter than the bore of the bolt, the latter .will act as a tell-tale just the same and while water may drip through the bore of the plug into the fire-box, it will not be to such an extent as to be objectionable. By boringthe plug as noted, greaterelasticity of action is permitted between the plug and the end of the bolt which, in some instances, may be preferable, since liability to fracture the bolt at its inner screw threaded end is avoided.

In view of the foregoing description, a detailed statement of the mode of operation seems to be unnecessary; but, it may be noted that the important features of the invention are the elimination of the head on the inner end of the bolt, the employment of a plug to securely fasten the bolt to the plate of the furnace and make a driven into the end of the bolt it will force the end of the same into firm engagement with the metal of the water-jacket.

2. In combination with the water-jacket of a furnace, a tubular bolt having its outer end headed and its inner end unheaded, and a plug driven into the inner end-of said bolt to prevent water leaking into the fire-box in case the body of i the bolt within the water-jacket becomes fractured.

3. A stay-bolt for furnaces having one end screw-threaded and headed and its other end screw-threaded and unheaded,-

said bolt being bored from end to end, in combinationwith a tapered plug cooperating with the unheaded end of the bolt and centered in said bore.

In testimony whereof I have hereunto signed my name in the presence of two1subscribing witnesses.

JOSEPH BOERO. Witnesses:

BLANGHE DUCROISE'I, E. E. GAUGHE. 

